1. Field of the Invention
The present invention relates to a railroad switch indicator positioned between the stockrails for visually signaling the position of a pair of railroad switchpoints independently of the mechanism for operating the switch. The switch indicator includes a mechanism that amplifies a small movement of the switchpoints and that defaults to a position signaling caution.
2. Brief Description of the Prior Art
In order to optionally switch a railroad train operating on one track to a second track, it is typical to provide a switch with a pair of switchpoints which are selectively movable horizontally to deflect the train toward one or the other of the tracks. The switchpoints may be driven by a manual or electrical powered mechanism. A signal is usually associated with the mechanism for operating the switch to visually indicate how the switch is lined. If a train runs through the switch or if the switchpoints are moved by vibrations of a train rolling over the track, the switchpoints may be moved into a mid position which is not reflected by the signal associated with the mechanism for operating the switch.
When a train runs through a switch, a flange on the wheels picks open the switchpoints. Depending on how sharp the wheels are, the distance that the switchpoints move may be much less than an inch and yet a misalignment of as little as 0.25 inch may result in a disastrous derailment. Manual mechanisms commonly miss such a small movement and even sophisticated electrically powered switch mechanisms with sensors for open and closed switchpoints may give a false signal.